307-01A Automatic Transmission, Transaxle- 4.0L: Description And Operation (page 44 of 47)

When the vehicle is travelling forwards, selecting reverse could cause transmission damage. To protect against this, 
reverse gear is prohibited if the vehicle is travelling forwards at a road speed above 5 mph (8 km/h). 
 

Cooling Strategy 

The purpose of the cooling strategy is to reduce engine and transmission temperatures during high load conditions, when 
towing a trailer for example. Under these conditions the engine and transmission may generate excessive heat. 
 
If the transmission fluid temperature increases to 125ºC (257ºF) or higher, the TCM employs the cooling strategy. The 
message 'TRANSMISSION OVERHEAT' is displayed in the message center. 
 
The strategy uses a specific shift and torque converter lock-up clutch map. This map allows torque converter clutch lock-
up and gear shifts to operate outside of their normal operation. This will reduce the engine speed and/or slip in the torque 
converter, therefore reducing heat generated by the engine and the transmission. 
 
If the transmission fluid temperature increases to 137ºC (278ºF) or higher, the transmission will use the default (limp 
home mode). 'H' is displayed in the gear position indicator. If the temperature exceeds 140ºC (284ºF), CAN bus 
transmission is disabled and 'E' is displayed in the gear position indicator. 
 
The cooling strategy is cancelled when the transmission fluid temperature decreases to less than 120ºC (248ºF) or below.
 

Curve Recognition 

Curve recognition is activated when high levels of lateral acceleration and/or steering angle are detected via the ABS 
module and steering angle sensor signals on the CAN bus. When this condition is detected, the TCM prevents the 
transmission from changing to a higher gear to assist with cornering. When the vehicle completes it manoeuvre, the 
transmission will shift to the correct ratio. 
 

Fast Off Recognition 

Fast off recognition is activated when the TCM detects that the driver has backed off the accelerator pedal quickly in a 
'change of mind' manoeuvre. This is detected by monitoring for a high level of negative pedal angle from the engine 
control module signal on the CAN bus. If this condition is detected, the TCM holds the current gear ratio to allow the driver 
to complete his original action without the need for a downshift. The mode remains active for a predetermined time period 
or if the driving style remains passive. 
 

Terrain Response™ Mode 

If the vehicle has the Terrain Response system fitted, the following additional modes are available. For additional 
information, refer to   

Ride and Handling Optimization

 (204-06 Ride and Handling Optimization) 

 
 
Grass/Gravel/Snow  
 
When the driver selects the Terrain Response grass/gravel/snow special program with the transfer box in either high or 
low range, the TCM uses a specific set of shift and torque converter maps to optimise the delivery of torque to the wheels 
and to minimise wheel slip in these terrains. To assist with the vehicle moving from a standstill, the TCM automatically 
selects 2nd gear in high range and 3rd gear in low range. This special program is fully integrated with hill mode to 
enhance vehicle control during ascents and descents. 
 
Mud/Ruts  
 
When the driver selects the Terrain Response mud/ruts special program with the transfer box in either high or low range, 
the TCM uses a specific set of shift and torque converter maps to optimise vehicle traction in this terrain. 
 
Sand  
 
When the driver selects the Terrain Response sand special program with the transfer box in either high or low range, the 
TCM uses a specific set of shift and torque converter maps to optimise the tractive performance in sand by holding onto 
gears longer and downshifting more readily. This mode is fully integrated with the hill mode to further enhance 
performance during ascents. 
 
Rock Crawl